DESCRIPTION: (taken from abstract) Amputation rates in the Medicare population have risen in the 1990s, and these rates vary by more than ten-fold across the country. The applicants hypothesize that significant differences in treatment patterns for peripheral arterial disease exist for Medicare beneficiaries, which influence the observed pattern of amputation rates. This proposal aims to answer the following questions: What invasive interventions are received by Medicare patients who present with peripheral arterial disease? 1. Controlling for disease severity, does bypass surgery and/or percutaneous transluminal angioplasty reduce the probability of amputation in the Medicare population? 2. Do differences in bypass surgery vary according to patient socioeconomic status, ethnicity, geographic location, or the availability of specialist physicians? 3. Do differences in amputation rates vary according to patient socioeconomic status, ethnicity, geographic location, or the type of treating physician or hospital? By characterizing current treatment patterns and identifying the most effective treatment methods, the applicant aims to derive information which will aid in reducing amputation rates in the Medicare population.